Airtightness measuring method of part of building

Abstract

To accurately measure airtightness of parts of a foundation-insulated building.SOLUTION: An airtightness measuring method includes the steps of: setting a house 1 to first to third states (S11, etc.); measuring an air flow rate Q and a pressure difference ΔP in each state (S12, etc.); calculating first to third gap areas A1 to A3 on the basis of the air flow rate Q and the pressure difference ΔP (S13, etc.); and calculating total equivalent gap areas B1 to B3 of first to third parts of the house 1 on the basis of the first to third gap areas A1 to A3 (S20). The airtightness measuring method further includes: a step S17 of communicating an underfloor space 15 and an outdoor space 16 with each other via a duct 61, and setting to a third state of causing a blower 22 to blow air from the indoor space 14 to the outdoor space 16 and causing an underfloor blower 23 to blow air from the outdoor space 16 via the duct 61 to the underfloor space 15; and a step S18 of measuring an air flow rate Q3 of the blower 22 and a pressure difference ΔP3 between the indoor space 14 and the outdoor space 16.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a method for measuring the airtightness of a building, and more particularly to a method for measuring the airtightness of a part of a building with basic heat insulation.

Background Art

[0002] In order to improve energy-saving performance, high airtightness has been required for recent buildings. In order to evaluate the airtightness of a building, it is necessary to measure the airtightness of the building. Regarding the measurement of the airtightness of a building, Non-Patent Document 1 describes a method of causing a pressure difference between the inside and outside of the building using a blower and testing the airtightness of the building and parts of the building.

[0003] Patent Document 1 describes a method of causing a pressure difference between the inside and outside of the building by performing intake or exhaust using an air supply and exhaust fan and a kitchen range fan provided in the building in advance, and measuring the airtightness of the building. Non-Patent Document 2 describes a method of measuring the airtightness (gap amount) of the foundation and base part of a building with basic heat insulation by measuring the pressure difference between the underfloor and the outside air and the amount of air exhausted from the underfloor while adjusting the flow rates of the fans so that the underfloor and the interior are at the same pressure, using a fan that directly exhausts outside air from under the floor and a fan that exhausts outside air from the living room.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Based on the results of measuring the airtightness of a building, in order to repair the building and improve its airtightness, it is preferable to measure the airtightness not only of the whole building but also of the parts of the building such as the ceiling, walls, floor, and foundation.

[0007] Patent Document 1 describes a method for measuring the airtightness of the whole building, but does not describe a method for measuring the airtightness of the parts of the building. Non-Patent Document 2 describes a method for measuring the airtightness of the foundation and base parts of a building with basic heat insulation, but when actually implementing this method, it is difficult to adjust the flow rate of each fan so that the pressure under the floor and in the room becomes equal. Therefore, with the method described in Non-Patent Document 2, the airtightness of the parts of the building cannot be accurately measured.

[0008] The present invention has been made in view of the above circumstances, and its object is to provide means for accurately measuring the airtightness of the parts of a building with basic heat insulation.

Means for Solving the Problems

[0009] (1) The airtightness measurement method of the present invention is an airtightness measurement method for a part of a building with basic heat insulation. In a first state where the indoor space and the underfloor space of the building are communicated and the blower blows air from the indoor space to the outdoor space of the building, a first measurement step of measuring the air volume in the blower and the pressure difference between the indoor space and the outdoor space is performed. A first calculation step of calculating a first gap area based on the air volume and the pressure difference measured in the first measurement step. In a second state where the indoor space and the outdoor space are communicated and the blower blows air from the underfloor space to the indoor space, a second measurement step of measuring the air volume in the blower and the pressure difference between the underfloor space and the indoor space is performed. A second calculation step of calculating a second gap area based on the air volume and the pressure difference measured in the second measurement step. In a third state where the underfloor space and the outdoor space are communicated via an airtight flow path, the blower blows air from the indoor space to the outdoor space, and a second blower different from the blower blows air from the outdoor space to the underfloor space via the airtight flow path, a third measurement step of measuring the air volume in the blower and the pressure difference between the indoor space and the outdoor space is performed. A third calculation step of calculating a third gap area based on the air volume and the pressure difference measured in the third measurement step. A fourth calculation step of calculating the total equivalent gap area of the first part including the foundation of the building based on the first gap area, the second gap area, and the third gap area is provided.

[0010] According to the above airtightness measurement method, three gap areas are calculated based on the air volumes and pressure differences measured in three states, and the total equivalent gap area of the first part including the foundation of the building is calculated based on the three gap areas, so that the airtightness of the first part can be measured. Further, in the third state, while blowing air from the indoor space to the outdoor space, blowing air from the outdoor space to the underfloor space to make the underfloor space and the outdoor space have the same pressure, the air volume and the pressure difference can be measured. Therefore, the third gap area can be accurately calculated, and the total equivalent gap area of the first part can be accurately calculated. Thus, the airtightness of the first part of the building with basic heat insulation can be accurately measured.

[0011] (2) Preferably, in the third measurement step, the air volume of the second blower may be controlled so that the underfloor space and the outdoor space have the same pressure.

[0012] According to the above configuration, by controlling the air volume of the second blower so that the underfloor space and the outdoor space have the same pressure, the ventilation volume and the pressure difference can be measured in a state where the underfloor space and the outdoor space have the same pressure. Therefore, the third gap area can be accurately calculated, and the total equivalent gap area of the first part can be accurately calculated.

[0013] (3) Preferably, in the third measurement step, the air volume of the second blower may be increased by a predetermined increment until the time during which the pressure difference between the underfloor space and the outdoor space is less than a predetermined amount continues for a predetermined time or more.

[0014] According to the above configuration, by increasing the air volume of the second blower by a predetermined increment until the time during which the pressure difference between the underfloor space and the outdoor space is less than a predetermined amount continues for a predetermined time or more, the ventilation volume and the pressure difference can be measured in a state where the underfloor space and the outdoor space have the same pressure. Therefore, the third gap area can be accurately calculated, and the total equivalent gap area of the first part can be accurately calculated.

[0015] (4) Preferably, in the fourth calculation step, the total equivalent gap area of the first part may be calculated by performing arithmetic operations on the first gap area, the second gap area, and the third gap area.

[0016] According to the above configuration, the total equivalent gap area of the first part can be easily calculated by performing arithmetic operations on the three gap areas.

[0017] (5) Preferably, in the fourth calculation step, based on the first gap area, the second gap area, and the third gap area, the total equivalent gap area of the second part including the ceiling and outer wall of the building, and the total equivalent gap area of the third part including the floor and partition wall of the building may be further calculated.

[0018] According to the above configuration, three clearance areas are calculated based on the ventilation volume and pressure difference measured in three states, and based on the three clearance areas, the total equivalent clearance area of the second part including the ceiling and outer wall and the third part including the floor and partition wall is calculated, whereby the airtightness of the second part and the third part can be measured. Further, in the third state, while blowing air from the indoor space to the outdoor space and blowing air from the outdoor space to the underfloor space to make the underfloor space and the outdoor space have equal pressure, the ventilation volume and pressure difference can be measured. Therefore, the third clearance area can be accurately calculated, and the total equivalent clearance area of the second part and the third part can be accurately calculated. Thus, the airtightness of the second part and the third part of the building with basic heat insulation can be accurately measured.

[0019] (6) Preferably, in the above fourth calculation step, the total equivalent clearance area of the first part, the total equivalent clearance area of the second part, and the total equivalent clearance area of the third part may be calculated by performing arithmetic operations on the first clearance area, the second clearance area, and the third clearance area.

[0020] According to the above configuration, by performing arithmetic operations on the three clearance areas, the total equivalent clearance area of each part can be easily calculated.

[0021] (7) Preferably, the above airtightness measurement method may further include a step of setting the building to the first state before the first measurement step, a step of setting the building to the second state before the second measurement step, and a step of setting the building to the third state before the third measurement step.

[0022] According to the above configuration, the building can be set to three states, and the ventilation volume and pressure difference can be measured in each state.

Effect of the Invention

[0023] According to the present invention, the airtightness of the parts of a building with basic heat insulation can be accurately measured.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

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Figure 8

Figure 9

[0025] Hereinafter, with reference to the drawings, an airtightness measurement method according to an embodiment of the present invention will be described. It should be noted that the embodiments described below are merely examples of the present invention, and it goes without saying that the embodiments of the present invention can be appropriately changed without changing the gist of the present invention.

[0026] [Outline of Airtightness Measurement Method] The airtightness measurement method according to the present embodiment is a method for measuring the airtightness of a part of a building with basic heat insulation. This airtightness measurement method includes steps of setting the building in first to third states, measuring the ventilation rate and the pressure difference in each state, calculating three gap areas based on the measured ventilation rate and pressure difference, and calculating the total equivalent gap area of three parts of the building based on the calculated three gap areas.

[0027] [Configuration of House 1] House 1 shown in Fig. 1 is an example of a building with basic insulation. House 1 includes a ceiling 2, an outer wall 3, a floor 4, a partition wall 5, a foundation 6, and a roof 7. The outer wall 3 has windows 11 and 12. The floor 4 has an underfloor inspection opening 13. The ceiling 2, the outer wall 3, and the floor 4 demarcate an indoor space 14. The floor 4 and the foundation 6 demarcate an underfloor space 15. The partition wall 5 is located in the indoor space 14. The roof 7 is located above the ceiling 2. Heat insulation materials 8 are provided on the indoor space 14 side of the ceiling 2 and the outer wall 3 and on the underfloor space 15 side of the rising part of the foundation 6.

[0028] Hereinafter, the space outside House 1 (the space other than the indoor space 14 and the underfloor space 15) is referred to as the outdoor space 16, the part including the foundation 6 is called the "first part", the part including the ceiling 2 and the outer wall 3 is called the "second part", and the part including the floor 4 and the partition wall 5 is called the "third part". Note that the underfloor space 15 is also called the foundation space.

[0029] [Configuration of Airtightness Measuring Machine 20] The airtightness measurement method according to this embodiment is executed, for example, using the airtightness measuring machine 20 shown in Fig. 2. The airtightness measuring machine 20 includes a main body device 21, a blower 22, and an underfloor blower 23. The main body device 21 includes a CPU 31, a memory 32, an input unit 33, a display unit 34, an interface unit (described as the I / F unit in Fig. 2) 35, a flow sensor 36, and two differential pressure sensors 37 and 38. The CPU 31 and the memory 32 function as a control unit 30.

[0030] Each component of the main body device 21 is connected to a bus 39 within the main body device 21. The CPU 31 controls the operations of the main body device 21, the blower 22, and the underfloor blower 23. The memory 32 stores the programs executed by the CPU 31 and functions as a working memory for the CPU 31. The input unit 33 has four buttons 41 to 44. The buttons 41 to 44 respectively correspond to the first measurement, the second measurement, the third measurement, and the evaluation. When any of the buttons 41 to 44 is pressed, the input unit 33 outputs a signal SS1 to the CPU 31 indicating that the button has been pressed and the type of the pressed button. The display unit 34 displays the airtightness measurement result and the like on the screen according to the control from the CPU 31.

[0031] The blower 22 and the underfloor blower 23 are connected to the interface unit 35. The control unit 30 outputs a signal CS1 for controlling the air volume of the blower 22 to the blower 22 and a signal CS2 for controlling the air volume of the underfloor blower 23 to the underfloor blower 23 via the interface unit 35.

[0032] Four or six vinyl tubes are connected to the airtightness measuring machine 20. The blower 22 is connected to the flow sensor 36 via the tubes 55 and 56. One end of the tube 55 is attached to the intake side of the blower 22, and one end of the tube 56 is attached to the exhaust side of the blower 22. The other ends of the tubes 55 and 56 are respectively connected to one end and the other end of the flow sensor 36. The flow sensor 36 measures the ventilation volume in the blower 22 and outputs a signal SS2 according to the measured ventilation volume.

[0033] The differential pressure sensor 37 is connected to the tubes 51 and 52. The differential pressure sensor 38 is connected to the tubes 53 and 54. One ends of the tubes 51 and 52 are respectively connected to one end and the other end of the differential pressure sensor 37. One ends of the tubes 53 and 54 are respectively connected to one end and the other end of the differential pressure sensor 38. The other ends E1 to E4 of the tubes 51 to 54 are in an open state. Hereinafter, the other ends E1 to E4 are referred to as open ends.

[0034] The open ends E1 to E4 are arranged in any one of the indoor space 14, the underfloor space 15, and the outdoor space 16 according to the type of measurement. The differential pressure sensor 37 measures the pressure difference between the space where the open end E1 is arranged and the space where the open end E2 is arranged, and outputs a signal SS3 corresponding to the measured pressure difference. The differential pressure sensor 38 measures the pressure difference between the space where the open end E3 is arranged and the space where the open end E4 is arranged, and outputs a signal SS4 corresponding to the measured pressure difference.

[0035] [First to Third Measurements] The measurer sets the house 1 to the first state (FIG. 3), the second state (FIG. 4), and the third state (FIG. 5), and measures the ventilation volume and the pressure difference using the airtightness measuring machine 20 in each state. For convenience of illustration in the drawings, the partition wall 5 is omitted in FIGS. 3 to 5.

[0036] In the first state (FIG. 3), the blower 22 is attached to the window 11, the window 12 is closed, and the underfloor inspection port 13 is opened. The open end E1 of the tube 51 is arranged in the indoor space 14, and the open end E2 of the tube 52 is arranged in the outdoor space 16. The blower 22 blows air from the indoor space 14 to the outdoor space 16 based on the output signal CS1 of the control unit 30. The control unit 30 acquires the ventilation volume Q1 in the blower 22 based on the output signal SS2 of the flow rate sensor 36, and acquires the pressure difference ΔP1 between the indoor space 14 and the outdoor space 16 based on the output signal SS3 of the differential pressure sensor 37.

[0037] The first state is a state in which the indoor space 14 and the underfloor space 15 are communicated, and the blower 22 blows air from the indoor space 14 to the outdoor space 16. In the first state, since the indoor space 14 and the underfloor space 15 (the dotted portion) are in a negative pressure state, air flows from the outdoor space 16 into the indoor space 14 and the underfloor space 15 through the gap of the first part including the foundation 6 and the gap of the second part including the ceiling 2 and the outer wall 3. In this state, the ventilation volume Q1 in the blower 22 and the pressure difference ΔP1 between the indoor space 14 and the outdoor space 16 are measured. The first measurement is the same as the measurement described in Non-Patent Document 1. In the first measurement, the underfloor blower 23 and the differential pressure sensor 38 are not used.

[0038] In the second state (Fig. 4), window 11 is closed, window 12 is open, and a blower 22 is attached to the underfloor inspection opening 13. Note that window 11 may be open. The open end E1 of the tube 51 is arranged in the underfloor space 15, and the open end E2 of the tube 52 is arranged in the indoor space 14. The blower 22 blows air from the underfloor space 15 to the indoor space 14 based on the output signal CS1 of the control unit 30. The control unit 30 obtains the ventilation volume Q2 of the blower 22 based on the output signal SS2 of the flow rate sensor 36, and obtains the pressure difference ΔP2 between the underfloor space 15 and the indoor space 14 based on the output signal SS3 of the differential pressure sensor 37.

[0039] The second state is a state in which the indoor space 14 and the outdoor space 16 are communicated, and the blower 22 blows air from the underfloor space 15 to the indoor space 14. In the second state, only the underfloor space 15 (the dotted pattern part) becomes negative pressure, so air flows into the underfloor space 15 from the indoor space 14 and the outdoor space 16 through the gaps of the first part including the foundation 6 and the gaps of the third part including the floor 4 and the partition wall 5. In this state, the ventilation volume Q2 of the blower 22 and the pressure difference ΔP2 between the underfloor space 15 and the indoor space 14 are measured. In the second measurement, the underfloor blower 23 and the differential pressure sensor 38 are not used.

[0040] In the third state (Fig. 5), the blower 22 is attached to the window 11, the underfloor blower 23 is attached to the window 12, and the underfloor inspection opening 13 is open. The exhaust side of the underfloor blower 23 and the underfloor inspection opening 13 are connected by a duct 61. The open end E1 of the tube 51 is arranged in the indoor space 14. The open ends E2 of the tube 52 and the open end E3 of the tube 53 are arranged in the outdoor space 16. The open end E4 of the tube 54 is arranged in the underfloor space 15. The blower 22 blows air from the indoor space 14 to the outdoor space 16 based on the output signal CS1 of the control unit 30. The underfloor blower 23 blows air from the outdoor space 16 to the underfloor space 15 based on the output signal CS2 of the control unit 30.

[0041] Based on the output signal SS2 of the flow sensor 36, the control unit 30 obtains the ventilation volume Q3 in the blower 22, and based on the output signal SS3 of the differential pressure sensor 37, obtains the pressure difference ΔP3 between the indoor space 14 and the outdoor space 16. In addition to this, the control unit 30 obtains the pressure difference ΔP4 between the underfloor space 15 and the outdoor space 16 based on the output signal SS4 of the differential pressure sensor 38, and controls the air volume of the underfloor blower 23 so that the underfloor space 15 and the outdoor space 16 become isobaric.

[0042] The third state is a state in which the underfloor space 15 and the outdoor space 16 are communicated via the duct 61, the blower 22 blows air from the indoor space 14 to the outdoor space 16, and the underfloor blower 23 blows air from the outdoor space 16 to the underfloor space 15 via the duct 61. In the third state, since only the indoor space 14 (the dotted pattern part) becomes negative pressure, air flows into the indoor space 14 from the underfloor space 15 and the outdoor space 16 via the gaps in the second part including the ceiling 2 and the outer wall 3 and the gaps in the third part including the floor 4 and the partition wall 5. In this state, while controlling the air volume of the underfloor blower 23 so that the underfloor space 15 and the outdoor space 16 become isobaric, the ventilation volume Q3 in the blower 22 and the pressure difference ΔP3 between the indoor space 14 and the outdoor space 16 are measured.

[0043] In the first to third measurements, the measurement of the ventilation volume and the pressure difference is repeatedly executed a predetermined number of times by switching the air volume of the blower 22. The number of measurements is, for example, 5 times.

[0044] [Details of the airtightness measurement method] Referring to FIG. 6, the airtightness measurement method according to this embodiment will be described. The airtightness measurement method according to this embodiment is executed using the airtightness measuring instrument 20. First, the measurer sets the house 1 to the first state (S11). Next, the measurer uses the airtightness measuring instrument 20 to measure the ventilation volume Q1 in the blower 22 and the pressure difference ΔP1 between the indoor space 14 and the outdoor space 16 in the first state (S12). Next, the measurer uses the airtightness measuring instrument 20 to calculate the first gap area A1 based on the ventilation volume Q1 and the pressure difference ΔP1 (S13). The airtightness measuring instrument 20 has a function of measuring the ventilation volume Q1 and the pressure difference ΔP1 and calculating the first gap area A1 (S41 and S42 in FIG. 7). The measurer presses the button 41 of the airtightness measuring instrument 20 and calls this function to execute S12 and S13.

[0045] Next, the measurer sets the house 1 to the second state (S14). Next, the measurer uses the airtightness measuring instrument 20 to measure the ventilation volume Q2 in the blower 22 and the pressure difference ΔP2 between the underfloor space 15 and the indoor space 14 in the second state (S15). Next, the measurer uses the airtightness measuring instrument 20 to calculate the second gap area A2 based on the ventilation volume Q2 and the pressure difference ΔP2 (S16). The airtightness measuring instrument 20 has a function of measuring the ventilation volume Q2 and the pressure difference ΔP2 and calculating the second gap area A2 (S51 and S52 in FIG. 7). The measurer presses the button 42 of the airtightness measuring instrument 20 and calls this function to execute S15 and S16.

[0046] Next, the measurer sets the housing 1 to the third state (S17). Next, the measurer uses the airtightness measuring device 20 to measure the ventilation volume Q3 in the blower 22 and the pressure difference ΔP3 between the indoor space 14 and the outdoor space 16 in the third state (S18). Next, the measurer uses the airtightness measuring device 20 to calculate the third gap area A3 based on the ventilation volume Q3 and the pressure difference ΔP3 (S19). The airtightness measuring device 20 has a function of measuring the ventilation volume Q3 and the pressure difference ΔP3 while controlling the air volume of the underfloor blower 23 so that the underfloor space 15 and the outdoor space 16 are at the same pressure, and calculating the third gap area A3 (S61 and S62 in FIG. 7). The measurer presses the button 43 of the airtightness measuring device 20 and calls this function to execute S17 and S18.

[0047] Next, the measurer uses the airtightness measuring device 20 to calculate the total equivalent gap area B1 of the first part, the total equivalent gap area B2 of the second part, and the total equivalent gap area B3 of the third part based on the first to third gap areas A1, A2, and A3 (S20). The airtightness measuring device 20 has a function of calculating the total equivalent gap areas B1 to B3 of the first to third parts based on the first to third gap areas A1, A2, and A3 (S71 in FIG. 7). The measurer presses the button 44 of the airtightness measuring device 20 and calls this function to execute S20.

[0048] [Operation of the airtightness measuring device 20] With reference to FIGS. 7 and 8, the operation of the control unit 30 of the airtightness measuring device 20 will be described. The processes shown in FIGS. 7 and 8 are executed by the CPU 31 executing a program (not shown) stored in the memory 32.

[0049] The control unit 30 determines whether a button of the input unit 33 has been pressed (S31). In S31, the control unit 30 determines whether any of the buttons 41 to 44 has been pressed. If a button has been pressed (S31: Yes), the control unit 30 proceeds to S32, and if no button has been pressed (S31: No), the control unit 30 proceeds to S31.

[0050] In the former case, the control unit 30 proceeds to the step corresponding to the type of the input instruction (S32). When the button 41 corresponding to the first measurement is pressed in S32 (S32: first measurement), the control unit 30 proceeds to S41. In this case, the control unit 30 measures the ventilation volume Q1 in the blower 22 and the pressure difference ΔP1 between the indoor space 14 and the outdoor space 16 by executing the measurement process shown in FIG. 8(A) (S41). Next, the control unit 30 calculates the first gap area A1 based on the measured ventilation volume Q1 and the pressure difference ΔP1 (S42). Next, the control unit 30 stores the calculated first gap area A1 in the memory 32 (S43) and proceeds to S31.

[0051] When the button 42 corresponding to the second measurement is pressed in S32 (S32: second measurement), the control unit 30 proceeds to S51. In this case, the control unit 30 measures the ventilation volume Q2 in the blower 22 and the pressure difference ΔP2 between the underfloor space 15 and the indoor space 14 by executing the measurement process shown in FIG. 8(A) (S51). Next, the control unit 30 calculates the second gap area A2 based on the measured ventilation volume Q2 and the pressure difference ΔP2 (S52). Next, the control unit 30 stores the calculated second gap area A2 in the memory 32 (S53) and proceeds to S31.

[0052] When the button 43 corresponding to the third measurement is pressed in S32 (S32: third measurement), the control unit 30 proceeds to S61. In this case, the control unit 30 measures the ventilation volume Q3 in the blower 22 and the pressure difference ΔP3 between the indoor space 14 and the outdoor space 16 while controlling the air volume of the underfloor blower 23 by executing the control / measurement process shown in FIG. 8(B) (S61). Next, the control unit 30 calculates the third gap area A3 based on the measured ventilation volume Q3 and the pressure difference ΔP3 (S62). Next, the control unit 30 stores the calculated third gap area A3 in the memory 32 (S63) and proceeds to S31.

[0053] When the button 44 corresponding to the evaluation is pressed in S32 (S32: Evaluation), the control unit 30 proceeds to S71. In this case, the control unit 30 calculates the total equivalent gap areas B1, B2, and B3 of the first to third parts based on the first to third gap areas A1, A2, and A3 stored in the memory 32 (S71). Next, the control unit 30 causes the calculated total equivalent gap areas B1, B2, and B3 of the first to third parts to be displayed on the display unit 34 (S72), and proceeds to S31.

[0054] [Details of Measurement Processing] In the measurement processing shown in FIG. 8(A), the control unit 30 first sets the value of the variable n to 1 (S81). Next, the control unit 30 controls the air volume of the blower 22 (S82). In S82, the control unit 30 controls the air volume of the blower 22 to an amount different from the previous measurement. Next, the control unit 30 measures the ventilation volume Q and the pressure difference ΔP in the blower 22 (S83). Next, the control unit 30 determines whether the value of the variable n is equal to a predetermined number of measurements (S84). If the value of the variable n is equal to the number of measurements (S84: Yes), the control unit 30 ends the measurement processing. If the value of the variable n is not equal to the number of measurements (S84: No), the control unit 30 proceeds to S85. In the latter case, the control unit 30 adds 1 to the value of the variable n (S85) and proceeds to S51.

[0055] In this way, in the measurement processing, the control unit 30 switches the air volume of the blower 22 and repeats the process of measuring the ventilation volume Q and the pressure difference ΔP in the blower 22 a predetermined number of times.

[0056] [Details of Control / Measurement Processing] The control / measurement process shown in FIG. 8(B) is obtained by adding S91 and S92 to the measurement process shown in FIG. 8(A). After executing S81, the control unit 30 proceeds to S91. Next, the control unit 30 determines whether or not a state where the pressure difference ΔP4 between the underfloor space 15 and the outdoor space 16 is less than 1 Pa has continued for 10 seconds (S91). If the control unit 30 determines Yes in S91 (S91: Yes), it proceeds to S82, and if it determines No in S91 (S91: No), it proceeds to S92. In the latter case, the control unit 30 increases the air volume of the underfloor blower 23 by 1% (S92) and proceeds to S91. After executing S85, the control unit 30 proceeds to S91.

[0057] In this way, in the control / measurement process, the control unit 30 switches the air volume of the blower 22 while controlling the air volume of the underfloor blower 23 so that the underfloor space 15 and the outdoor space 16 become equal in pressure, and measures the ventilation volume Q3 and the pressure difference ΔP3 in the blower 22, and repeats the process a predetermined number of times.

[0058] [Calculation of the First to Third Gap Areas A1 to A3] In S42, S52, and S62, the control unit 30 calculates the gap area A based on the ventilation volume Q and the pressure difference ΔP by the following method. As described in Non-Patent Document 1, the following equation (1) holds between the indoor-outdoor pressure difference ΔP and the ventilation volume Q. Note that equation (1) is called the ventilation characteristic equation. Q = a(ΔP) 1 / n …(1) However, in equation (1), a is the ventilation rate and n is the gap characteristic value. The ventilation rate a is the ventilation volume per hour when the indoor-outdoor pressure difference is 1 Pa. The gap characteristic value n takes a value within the range of 1 to 2, approaches 1 when the gap is small, and approaches 2 when the gap is large like a simple opening. The unit of the pressure difference ΔP is Pa, the unit of the ventilation volume Q is m 3 / h, the unit of the coefficient a is m 3 / (h·Pa 1 / n )), and the characteristic value n is dimensionless.

[0059] From equation (1), the following equation (2) is derived. logQ = loga + (1 / n)·logΔP …(2) As shown in FIG. 9, the relationship between the pressure difference ΔP and the ventilation rate Q is linear on a double logarithmic graph. By performing a regression analysis using the least squares method based on Equation (2), the ventilation rate a and the gap characteristic value n can be calculated.

[0060] The gap area A is calculated by the following Equation (3) based on the ventilation rate a and the gap characteristic value n. A = (1 / 0.36)·a(ρ / 2) 1 / 2 ·(9.8) (1 / n-1 / 2) …(3) However, in Equation (3), ρ is the density of air. The unit of the gap area A is cm 2 , and the unit of the air density ρ is g / cm 3 . Note that the gap area A corresponds to the total equivalent gap area αA in Non-Patent Document 1.

[0061] In S42, the control unit 30 calculates the first gap area A1 by the above method with the ventilation rate being Q1 and the pressure difference being ΔP1. In S52, the control unit 30 calculates the second gap area A2 by the above method with the ventilation rate being Q2 and the pressure difference being ΔP2, and in S62, the control unit 30 calculates the third gap area A3 by the above method with the ventilation rate being Q3 and the pressure difference being ΔP3.

[0062] [Calculation of the total equivalent gap areas B1 to B3 of the first to third parts] In S71, the control unit 30 calculates the total equivalent gap areas B1 to B3 of the first to third parts based on the first to third gap areas A1 to A3 by the following method. In the first state, the indoor space 14 and the underfloor space 15 are in communication and form one closed space. This closed space is partitioned by the first part (the part including the foundation 6) and the second part (the part including the ceiling 2 and the outer wall 3). Therefore, the first gap area A1 calculated in S42 is equal to the sum of the total equivalent gap area B1 of the first part and the total equivalent gap area B2 of the second part. Thus, the following Equation (4a) holds. A1 = B1 + B2 …(4a)

[0063] In the second state, the underfloor space 15 becomes a closed space. This closed space is partitioned by the first part and the third part (the part including the floor 4 and the partition wall 5). Therefore, the second gap area A2 calculated in S52 is equal to the sum of the total equivalent gap area B1 of the first part and the total equivalent gap area B3 of the third part. Thus, the following equation (4b) holds. A2 = B1 + B3 …(4b)

[0064] In the third state, the indoor space 14 becomes a closed space. This closed space is partitioned by the second part and the third part. Therefore, the third gap area A3 calculated in S62 is equal to the sum of the total equivalent gap area B2 of the second part and the total equivalent gap area B3 of the third part. Thus, the following equation (4c) holds. A3 = B2 + B3 …(4c)

[0065] The control unit 30 calculates the total equivalent gap areas B1 to B3 of the first to third parts by solving equations (4a) to (4c) as a system of three linear equations with three unknowns in S71. For example, the control unit 30 calculates the value S according to the following equation (5), and calculates the total equivalent gap areas B1 to B3 of the first to third parts according to the following equations (6a) to (6c). S = (A1 + A2 + A3) / 2 …(5) B1 = S - A3 …(6a) B2 = S - A2 …(6b) B3 = S - A1 …(6c) The control unit 30 calculates the total equivalent gap areas B1 to B3 of the first to third parts by performing arithmetic operations on the first to third gap areas A1 to A3 in S71.

[0066] In the above description, the underfloor blower 23 is an example of the second blower. The duct 61 is an example of the airtight flow path. S12 and S41 are examples of the first measurement steps. S13 and S42 are examples of the first calculation steps. S15 and S51 are examples of the second measurement steps. S16 and S52 are examples of the second calculation steps. S18 and S61 are examples of the third measurement steps. S19 and S62 are examples of the third calculation steps. S20 and S71 are examples of the fourth calculation steps. 1 Pa in S91 is an example of a predetermined amount, and 10 seconds is an example of a predetermined time. 1% in S92 is an example of a predetermined increment.

[0067] [Operational Effects of the Embodiment] As described above, the airtightness measurement method according to the embodiment of the present invention includes a first measurement step (S12 and S41) of measuring the ventilation volume Q1 and the pressure difference ΔP1 in the first state, a first calculation step (S13 and S42) of calculating the first gap area A1 based on the ventilation volume Q1 and the pressure difference ΔP1, a second measurement step (S15 and S51) of measuring the ventilation volume Q2 and the pressure difference ΔP2 in the second state, a second calculation step (S16 and S52) of calculating the second gap area A2 based on the ventilation volume Q2 and the pressure difference ΔP2, a third measurement step (S18 and S61) of measuring the ventilation volume Q3 and the pressure difference ΔP3 in the third state, a third calculation step (S19 and S62) of calculating the third gap area A3 based on the ventilation volume Q3 and the pressure difference ΔP3, and a fourth calculation step (S20 and S71) of calculating the total equivalent gap area A1 of the first part including the foundation 6 of the building (House 1) based on the first to third gap areas A1 to A3.

[0068] Therefore, according to the airtightness measurement method according to this embodiment, three gap areas A1 to A3 are calculated based on the ventilation volume Q and the pressure difference ΔP measured in three states, and the total equivalent gap area B1 of the first part is calculated based on the three gap areas A1 to A3, whereby the airtightness of the first part can be measured. Further, in the third state, while blowing air from the indoor space 14 to the outdoor space 16 and blowing air from the outdoor space 16 to the underfloor space 15, the ventilation volume Q3 and the pressure difference ΔP3 can be measured in a state where the underfloor space 15 and the outdoor space 16 are at the same pressure. Therefore, the third gap area A3 can be accurately calculated, and the total equivalent gap area B1 of the first part can be accurately calculated. Thus, the airtightness of the first part of the well-insulated house 1 can be accurately measured.

[0069] Further, in the third measurement step, the air volume of the underfloor blower 23 (second blower) is controlled so that the underfloor space 15 and the outdoor space 16 are at the same pressure. Thereby, the ventilation volume Q3 and the pressure difference ΔP3 can be measured in a state where the underfloor space 15 and the outdoor space 16 are at the same pressure. Therefore, the third gap area A3 can be accurately calculated, and the total equivalent gap area B1 of the first part can be accurately calculated.

[0070] Further, in the third measurement step, the air volume of the underfloor blower 23 is increased by a predetermined increment (1%) at a time until the time when the pressure difference ΔP4 between the underfloor space 15 and the outdoor space 16 is less than 1 Pa (predetermined amount) continues for 10 seconds (predetermined time) or more. Therefore, the ventilation volume Q3 and the pressure difference ΔP3 can be measured in a state where the underfloor space 15 and the outdoor space 16 are at the same pressure. Thus, the third gap area A3 can be accurately calculated, and the total equivalent gap area B1 of the first part can be accurately calculated.

[0071] Further, in the fourth calculation step, the total equivalent gap area B1 of the first part is calculated by performing arithmetic operations on the first to third gap areas A1 to A3. Therefore, the total equivalent gap area B1 of the first part can be easily calculated by performing arithmetic operations on the three gap areas A1 to A3.

[0072] In the fourth calculation step, based on the first to third gap areas A1 to A3, the total equivalent gap area B2 of the second part and the total equivalent gap area B3 of the third part are further calculated. Therefore, by calculating the three gap areas A1 to A3 based on the ventilation volume Q and the pressure difference ΔP measured in three states, and calculating the total equivalent gap areas B2 and B3 of the second part and the third part based on the three gap areas A1 to A3, the airtightness of the second part and the third part can be measured. In the third state, while blowing air from the indoor space 14 to the outdoor space 16, air is also blown from the outdoor space 16 to the underfloor space 15, and the ventilation volume Q3 and the pressure difference ΔP3 can be measured in a state where the underfloor space 15 and the outdoor space 16 are at the same pressure. Therefore, the third gap area A3 can be accurately calculated, and the total equivalent gap areas B2 and B3 of the second part and the third part can be accurately calculated. Thus, the airtightness of the second part and the third part of the building with basic insulation can be accurately measured.

[0073] Also, in the fourth calculation step, by performing arithmetic operations on the first to third gap areas A1 to A3, the total equivalent gap areas B1 to B3 of the first to third parts are calculated. Therefore, by performing arithmetic operations on the three gap areas A1 to A3, the total equivalent gap areas B1 to B3 of each part can be easily calculated.

[0074] The airtightness measurement method further includes a step (S11) of setting the building to the first state before the first measurement step, a step (S14) of setting the building to the second state before the second measurement step, and a step (S17) of setting the building to the third state before the third measurement step. Therefore, the building can be set to three states, and the ventilation volume Q and the pressure difference ΔP can be measured in each state.

[0075] Since the airtightness of a house depends on the construction of the house, airtightness measurement at the construction site is essential. In order to improve the airtightness of a house, it is effective to determine the gap area of each part of the house and repair the part with a large gap area. In particular, in a house with a high airtightness specification, the gap area of the whole house is small, and the gap area of each part is even smaller, so it is necessary to accurately determine the gap area of each part.

[0076] Generally, the pressure difference between the underfloor space and the outdoor space of a house is likely to vary due to disturbances such as external wind. In the airtightness measurement method described in Non-Patent Document 2, since there is no means to reduce the pressure difference between the underfloor space and the outdoor space, the pressure difference between the underfloor space and the outdoor space varies due to the influence of disturbances, and the gap area of each part of the house cannot be accurately measured.

[0077] On the other hand, according to the airtightness measurement method according to this embodiment, in the third state, by controlling the air volume of the underfloor blower 23 so that the underfloor space 15 and the outdoor space 16 have the same pressure, the influence of disturbances is eliminated, and the gap area of each part of the house 1 can be accurately measured. Therefore, based on the accurate measurement results, the airtightness of the house 1 can be further improved. Further, by using the airtightness measuring machine 20 to automatically control the air volume of the underfloor blower 23, the gap area of each part of the house 1 can be accurately and easily measured.

[0078] [Modification Example] Regarding the airtightness measurement method according to this embodiment, various modification examples can be configured. The airtightness measurement method according to the modification example may be executed using an airtightness measuring machine having a configuration different from that of the airtightness measuring machine 20. For example, the airtightness measuring machine may be provided with two temperature sensors outside the main body device 21. The two temperature sensors are respectively arranged in the same space as the open ends E1 and E2 of the tubes 51 and 52, and measure the temperature of each space. When the difference between the two measured temperatures is greater than or equal to a predetermined value, the control unit 30 may not execute the airtightness measurement method. Alternatively, the control unit 30 may calculate the density ρ of the air with reference to the measured temperature.

[0079] In the airtightness measurement method according to this embodiment, in S91, the control unit 30 determines whether or not a state where the pressure difference ΔP4 between the underfloor space 15 and the outdoor space 16 is less than 1 Pa continues for 10 seconds, and in S92, the air volume of the underfloor blower 23 is increased by 1%. In the airtightness measurement method according to the modification, the threshold value of the pressure difference ΔP4, the threshold value of the state continuation time, and the increase rate of the air volume may be values other than the above. For example, in S91, the control unit 30 may determine whether or not a state where the pressure difference ΔP4 is less than 0.5 Pa continues for 5 seconds, and in S92, the air volume of the underfloor blower 23 may be increased by 2%.

[0080] In the airtightness measurement method according to the modification, the first to third measurements may be executed in any order. For example, in the airtightness measurement method according to the modification, first, S14 to S16 may be executed, then S17 to S19 may be executed, then S11 to S13 may be executed, and finally S20 may be executed.

[0081] In the airtightness measurement method according to the modification, the measurer may calculate the total equivalent gap areas B1 to B3 of the first to third parts based on the first to third gap areas A1 to A3 without using the airtightness measuring device 20. After the measurer calculates the first to third gap areas A1 to A3 using the airtightness measuring device 20, the total equivalent gap areas B1 to B3 of the first to third parts can be calculated by performing simple calculations on the calculated first to third gap areas A1 to A3.

[0082] In the airtightness measurement method according to the modification, after the measurer measures the ventilation volume Q and the pressure difference ΔP using the airtightness measuring device 20, the measurer may calculate the first to third gap areas A1 to A3 without using the airtightness measuring device 20. For example, the measurer may input the measured ventilation volume Q and pressure difference ΔP into spreadsheet software and have the spreadsheet software perform a regression analysis by the least squares method to calculate the first to third gap areas A1 to A3. In this case, the measurer calculates the first to third total equivalent gap areas B1 to B3 without using the airtightness measuring device 20.

[0083] The airtightness measurement method according to the modification example may further include a step of calculating the equivalent gap areas C1 to C3 of the first to third parts. The equivalent gap area C is a value obtained by dividing the total equivalent gap area A by the area S of the part, and is also called the C value. By calculating the equivalent gap area C of each part, the airtightness of each part can be easily evaluated.

[0084] [Appendix 1] An airtightness measurement method for a part of a building with basic insulation, In a first state where the indoor space and the underfloor space of the building are communicated and the blower blows air from the indoor space to the outdoor space of the building, a first measurement step of measuring the ventilation volume in the blower and the pressure difference between the indoor space and the outdoor space; A first calculation step of calculating a first gap area based on the ventilation volume and the pressure difference measured in the first measurement step; In a second state where the indoor space and the outdoor space are communicated and the blower blows air from the underfloor space to the indoor space, a second measurement step of measuring the ventilation volume in the blower and the pressure difference between the underfloor space and the indoor space; A second calculation step of calculating a second gap area based on the ventilation volume and the pressure difference measured in the second measurement step; In a third state where the underfloor space and the outdoor space are communicated via an airtight flow path, the blower blows air from the indoor space to the outdoor space, and a second blower different from the blower blows air from the outdoor space to the underfloor space via the airtight flow path, a third measurement step of measuring the ventilation volume in the blower and the pressure difference between the indoor space and the outdoor space; A third calculation step of calculating a third gap area based on the ventilation volume and the pressure difference measured in the third measurement step; A fourth calculation step of calculating the total equivalent gap area of the first part including the foundation of the building based on the first gap area, the second gap area, and the third gap area. An airtightness measurement method comprising the steps.

[0085] [Appendix 2] The airtightness measurement method described in Appendix 1, in which in the third measurement step, the air volume of the second blower is controlled so that the under-floor space and the outdoor space have the same pressure.

[0086] [Appendix 3] The airtightness measurement method described in Appendix 2, in which in the third measurement step, the air volume of the second blower is increased by a predetermined increment until the time during which the pressure difference between the under-floor space and the outdoor space is less than a predetermined amount continues for a predetermined time or more.

[0087] [Appendix 4] The airtightness measurement method described in Appendix 1, in which in the fourth calculation step, the total equivalent gap area of the first part is calculated by performing arithmetic operations on the first gap area, the second gap area, and the third gap area.

[0088] [Appendix 5] The airtightness measurement method described in Appendix 1, in which in the fourth calculation step, based on the first gap area, the second gap area, and the third gap area, the total equivalent gap area of the second part including the ceiling and outer wall of the building, and the total equivalent gap area of the third part including the floor and partition walls of the building are further calculated.

[0089] [Appendix 6] The airtightness measurement method described in Appendix 5, in which in the fourth calculation step, the total equivalent gap area of the first part, the total equivalent gap area of the second part, and the total equivalent gap area of the third part are calculated by performing arithmetic operations on the first gap area, the second gap area, and the third gap area.

[0090] [Appendix 7] Before the first measurement step, a step of setting the building to the first state, Before the second measurement step, a step of setting the building to the second state, Before the third measurement step, a step of setting the building to the third state, and the airtightness measurement method according to any one of Appendices 1 to 6, further comprising these steps.

Explanation of Signs

[0091] 1 ··· House (building) 2 ··· Ceiling 3 ··· Outer wall 4 ··· Floor 5 ··· Partition wall 6 ··· Foundation 11, 12 ··· Window 13 ··· Under - floor inspection opening 14 ··· Indoor space 15 ··· Under - floor space 16 ··· Outdoor space 20 ··· Airtightness measuring machine 21 ··· Main body device 22 ··· Blower 23 ··· Under - floor blower (second blower) 30 ··· Control unit 36 ··· Flow sensor 37, 38 ··· Differential pressure sensor 61 ··· Duct (airtight flow path)

Claims

1. A method for measuring the airtightness of a part of a building with basic heat insulation, comprising: a first measuring step of communicating the indoor space and the underfloor space of the building, and in a first state where a blower blows air from the indoor space to the outdoor space of the building, measuring the ventilation volume of the blower and the pressure difference between the indoor space and the outdoor space; a first calculating step of calculating a first gap area based on the ventilation volume and the pressure difference measured in the first measuring step; a second measuring step of communicating the indoor space and the outdoor space, and in a second state where the blower blows air from the underfloor space to the indoor space, measuring the ventilation volume of the blower and the pressure difference between the underfloor space and the indoor space; a second calculating step of calculating a second gap area based on the ventilation volume and the pressure difference measured in the second measuring step; a third measuring step of communicating the underfloor space and the outdoor space via an airtight flow path, blowing air from the indoor space to the outdoor space by the blower, and blowing air from the outdoor space to the underfloor space via the airtight flow path by a second blower different from the blower, and measuring the ventilation volume of the blower and the pressure difference between the indoor space and the outdoor space in a third state; a third calculating step of calculating a third gap area based on the ventilation volume and the pressure difference measured in the third measuring step; a fourth calculating step of calculating the total equivalent gap area of a first part including the foundation of the building based on the first gap area, the second gap area, and the third gap area. An airtightness measurement method comprising the steps.

2. The airtightness measurement method according to claim 1, wherein in the third measuring step, the air volume of the second blower is controlled so that the underfloor space and the outdoor space are at the same pressure.

3. The airtightness measurement method according to claim 2, wherein in the third measuring step, the air volume of the second blower is increased by a predetermined increment until the time when the pressure difference between the underfloor space and the outdoor space is less than a predetermined amount continues for a predetermined time or more.

4. The airtightness measurement method according to claim 1, wherein in the fourth calculating step, the total equivalent gap area of the first part is calculated by performing arithmetic operations on the first gap area, the second gap area, and the third gap area.

5. In the fourth calculation step, based on the first gap area, the second gap area, and the third gap area, the total equivalent gap area of the second part including the ceiling and outer wall of the building, and the total equivalent gap area of the third part including the floor and partition wall of the building are further calculated. The airtightness measurement method according to claim 1.

6. In the fourth calculation step, by performing arithmetic operations on the first gap area, the second gap area, and the third gap area, the total equivalent gap area of the first part, the total equivalent gap area of the second part, and the total equivalent gap area of the third part are calculated. The airtightness measurement method according to claim 5.

7. Before the first measurement step, a step of setting the building to the first state; Before the second measurement step, a step of setting the building to the second state; Before the third measurement step, a step of setting the building to the third state; The airtightness measurement method according to any one of claims 1 to 6, further comprising the above steps.

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